WASHINGTON - The deaths of Osama bin Laden and other key figures have put al-Qaida on "a path of decline", said a US report released on Tuesday.

The Country Reports on Terrorism 2011 issued by the State Department hailed the killing of bin Laden, founder and sole leader of the terrorist group for 22 years, calling it an event that "highlighted a landmark year in the global effort to counter terrorism."

The report said other high-profile deaths like that of Atiya Abdul Rahman, al-Qaida's second-in-command after bin Laden's death, put the network "on a path of decline that will be difficult to reverse."

However, the terror group remains an "enduring and serious" threat to US national security due to its "resilience" and capability to conduct regional and transnational attacks, the report cautioned.

It regarded the al-Qaida in the Arabian Peninsula as a " particularly serious threat," saying the affiliate had taken control of territory in southern Yemen and was exploiting unrest in the poor country to advance plots against regional and Western interests.

Al-Qaida in the Islamic Maghreb, its offshoot in Iraq and al- Shabaab are also among top US concerns.